The present invention relates to a connector and in particular, to a connector adapted to connect sheet-shaped connection targets exemplified by FPCs (flexible printed circuits), FFCs (flexible flat cables) and the like.
As a connector of this type, for example, JP 2007-122894 A discloses a connector 81 as illustrated in FIG. 9. The connector 81 is fixed on a mounting board 82. When an actuator 86 is rotated with a connection end of a sheet-shaped connection target 85 being inserted into a recessed insertion section 84 of a housing 83, it establishes electrical connections between a plurality of connection terminals formed at the connection target 85 and a plurality of contacts 87 of the connector 81, and the connection target 85 is held by the connector 81.
However, since a bottom portion of the housing 83 is positioned under the insertion section 84 and the insertion section 84 is formed on the bottom portion, in order to insert the connection target 85 into the insertion section 84 of the connector 81, a connection end of the connection target 85 needs to be advanced toward the insertion section 84 in a state that the connection end of the connection target 85 is brought up from the top surface of the mounting board 82 to a predetermined height so as to be placed at a height of the insertion section 84. Thus, it has been difficult to smoothly perform an insertion operation of the connection target 85. If the connection target 85 is advanced toward the connector 81 along the top surface of the mounting board 82, the connection end of the connection target 85 collides against the bottom portion of the housing 83, whereby the insertion thereof is blocked.
In particular, a width of the connection target 85 of sheet shape increases with increasing number of pins and accordingly, a deflection tends to occur at the connection target 85. Consequently, it makes the insertion operation of the connection target 85 difficult and troublesome.
On the other hand, in a connector 88 disclosed by JP 2011-181210 A, a plurality of contacts 91 are each mounted by soldering on a solder pad 93 of a mounting board 92 under an entrance area of an insertion section 90 into which a connection target 89 is inserted, as illustrated in FIG. 10A. With this configuration, a lower portion of the insertion section 90 is not occupied by a bottom portion of a housing 94. But, under the entrance of the insertion section 90, the contacts 91 have upright ends 95 which stand substantially perpendicular to the top surface of the mounting board 92 and accordingly, a connection end of the connection target 89 needs to be advanced toward the insertion section 90 in a state that the connection end of the connection target 89 is brought up from the top surface of the mounting board 92 to a predetermined height so as to be placed at a height of the insertion section 90, as well as the connector 81 illustrated in FIG. 9. If the connection target 89 is advanced toward the connector 88 along the top surface of the mounting board 92, the connection end of the connection target 89 collides against the upright ends 95 of the contacts 91, whereby the insertion thereof is blocked.
Aside from that, in the connector 88, slopes 96 for guiding the insertion of the connection target 89 are formed at both side ends of the entrance of the insertion section 90, as illustrated in FIG. 10B.
However, the connection target 89 needs to be inserted after both side ends of the connection end of the connection target 89 are placed on the corresponding slopes 96. In the case where the connection target 89 is inserted obliquely with respect to the connector 88 so that the connection target 89 is inserted with one of both the side ends of the connection end of the connection target 89 being solely placed on the corresponding slope 96 of the housing 94, the connection end of the connection target 89 is caused to collide against some upright ends 95 of the contacts 91 at the other of both the side ends, and the connection target 89 is thus prevented from being properly inserted into the insertion section 90.
In addition, the housing 94 is generally produced by molding a resin material with an electrical insulation property. Since, due to the limitation of fabrication technology, it is difficult to form a sharply-peaked tip with such a material, a small upright end 97 standing substantially perpendicular to the top surface of the mounting board 92 is formed at an end of each slope 96 as illustrated in FIGS. 10A and 10B. Consequently, if the connection target 89 is tried to be inserted into the connector 88 along the top surface of the mounting board 92, both the side ends of the connection end of the connection target 89 collide against the upright ends 97 of the housing 94.
Furthermore, when each of the contacts 91 is soldered on the corresponding solder pad 93 on the mounting board 92, usually a solder fillet is formed and a slant constituted of a surface of the solder fillet is formed to extend from a surface of the solder pad 93 to the contact 91. However, the upright ends 95 of the contacts 91 are not necessarily all covered by the formed slants and, even if at least one of the upright ends 95 of the contacts 91 is exposed, still the connection target 89 collides against the exposed upright end 95 so that the connection target 89 cannot be smoothly inserted.
Thus, conventional connectors have a problem of difficulty in easy and smooth insertion of a sheet-shaped connection target.